<b>Chloroform Fraction of <i>Mitracarpus hirtus</i> Induces p53-Mediated Cell Cycle Arrest and Apoptosis in MCF-7 Breast Cancer Cells</b>

Background: Breast cancer remains a serious life-threatening disease to women worldwide, contributing to a high rate of mortality among women. A critical molecular event implicated in breast cancer progression is the dysregulation of the tumour suppressor gene p53, which plays a key role in DNA repair and the regulation of the cell cycle and proliferation of cells. Mitracarpus hirtus, traditionally used to treat various ailments, presents a largely untapped resource of agents with promising anti-cancer potential. This study examined the anti-breast cancer properties of the chloroform fraction of M. hirtus, with particular emphasis on the regulation of p53 upstream and downstream target genes. Methods: The leaves of M. hirtus were extracted and fractionated using solvents with increasing polarity to obtain hexane, chloroform and water fractions. Anti-proliferative effects of chloroform fraction were evaluated on MCF-7 cells using a neutral red assay. Cell cycle progression and apoptosis were analysed using flow cytometry with PI and Annexin V-7AAD staining, respectively. Real-time PCR was used to assess the expression profiles of apoptotic-related genes. Results: The results revealed a significant inhibition of MCF-7 cell growth by the chloroform fraction of M. hirtus (IC50 = 9.54 µg/mL). This fraction induced apoptosis in MCF-7 cells, increasing the population of cells in the early and late apoptotic stages. The pro-apoptotic genes p53, Bax, and Casp3 were upregulated, while the anti-apoptotic gene Bcl2 was downregulated. Additionally, UCK2 and STAT3 gene suppression was observed, with STAT3 showing the most significant change. The fraction also significantly inhibited cell cycle progression, causing an accumulation of cells in the G0/G1 phase. Conclusion: Our study shows the ability of M. hirtus to inhibit breast cancer cell growth and induce apoptosis, presenting promising opportunities for further research in breast cancer treatment.